Which delivery method should I use?
2 min read · Last updated June 2026
Use Picture tag (the default) unless you have a specific reason not to. It works on almost any host and is safe behind a CDN, so most sites should leave it on and change nothing.
The three modes
SlashImage gives you three ways to hand WebP and AVIF to visitors. They all end with smaller images, but they get there differently, and the right pick depends on your host and whether a CDN sits in front of your site.
| Method | How it works | When to use |
|---|---|---|
| Picture tag (default) | Rewrites the images on your pages into <picture> tags, so each visitor's browser picks the format it supports. CDN-safe, because every format is its own file with its own address. Only touches standard image tags (content, featured, responsive sizes), not CSS backgrounds. | Almost any site, including shared hosting with no server access, and any site behind a CDN. |
| Server rewrite | Your web server picks the format instead of the page HTML. A rule in Apache's .htaccess or your NGINX config reads the browser's Accept header and serves the matching file. Covers more, including CSS background images. | Only when you want the swap at the server and you are not behind a default CDN. On Apache, the plugin writes the .htaccess rules automatically. On NGINX, configure it manually. Extra setup needed behind Cloudflare. |
| None (delivery off) | Still optimizes your images and creates WebP and AVIF versions, but does not change how they are served. | When something else already handles WebP and AVIF for you, such as a CDN that converts on the fly. |
See also
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